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mmc: Downgrade SD/MMC from UHS/HS200/HS400 modes before boot

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Older kernel versions or systems which do not connect eMMC reset line
properly may not be able to handle situations where either the eMMC
is left in HS200/HS400 mode or SD card in UHS modes by the bootloader
and may misbehave. Downgrade the eMMC to HS/HS52 mode and/or SD card
to non-UHS mode before booting the kernel to allow such older kernels
to work with modern U-Boot.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Tom Rini <trini@konsulko.com>
This commit is contained in:
Marek Vasut 2019-01-29 04:45:51 +01:00 committed by Marek Vasut
parent d391c13c99
commit fceea99268
3 changed files with 51 additions and 0 deletions
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19
drivers/mmc/mmc-uclass.c
View file

@ -368,6 +368,19 @@ static int mmc_blk_probe(struct udevice *dev)
return 0;
}
#if CONFIG_IS_ENABLED(MMC_UHS_SUPPORT) || \
CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \
CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
static int mmc_blk_remove(struct udevice *dev)
{
struct udevice *mmc_dev = dev_get_parent(dev);
struct mmc_uclass_priv *upriv = dev_get_uclass_priv(mmc_dev);
struct mmc *mmc = upriv->mmc;
return mmc_deinit(mmc);
}
#endif
static const struct blk_ops mmc_blk_ops = {
.read = mmc_bread,
#if CONFIG_IS_ENABLED(MMC_WRITE)
@ -382,6 +395,12 @@ U_BOOT_DRIVER(mmc_blk) = {
.id = UCLASS_BLK,
.ops = &mmc_blk_ops,
.probe = mmc_blk_probe,
#if CONFIG_IS_ENABLED(MMC_UHS_SUPPORT) || \
CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \
CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
.remove = mmc_blk_remove,
.flags = DM_FLAG_OS_PREPARE,
#endif
};
#endif /* CONFIG_BLK */

26
drivers/mmc/mmc.c
View file

@ -2781,6 +2781,32 @@ int mmc_init(struct mmc *mmc)
return err;
}
#if CONFIG_IS_ENABLED(MMC_UHS_SUPPORT) || \
CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \
CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
int mmc_deinit(struct mmc *mmc)
{
u32 caps_filtered;
if (!mmc->has_init)
return 0;
if (IS_SD(mmc)) {
caps_filtered = mmc->card_caps &
~(MMC_CAP(UHS_SDR12) | MMC_CAP(UHS_SDR25) |
MMC_CAP(UHS_SDR50) | MMC_CAP(UHS_DDR50) |
MMC_CAP(UHS_SDR104));
return sd_select_mode_and_width(mmc, caps_filtered);
} else {
caps_filtered = mmc->card_caps &
~(MMC_CAP(MMC_HS_200) | MMC_CAP(MMC_HS_400));
return mmc_select_mode_and_width(mmc, caps_filtered);
}
}
#endif
int mmc_set_dsr(struct mmc *mmc, u16 val)
{
mmc->dsr = val;

6
include/mmc.h
View file

@ -690,6 +690,12 @@ int mmc_initialize(bd_t *bis);
int mmc_init(struct mmc *mmc);
int mmc_send_tuning(struct mmc *mmc, u32 opcode, int *cmd_error);
#if CONFIG_IS_ENABLED(MMC_UHS_SUPPORT) || \
CONFIG_IS_ENABLED(MMC_HS200_SUPPORT) || \
CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
int mmc_deinit(struct mmc *mmc);
#endif
/**
* mmc_of_parse() - Parse the device tree to get the capabilities of the host
*